Resumo:
The Brevipalpus yothersi Baker mite is a vector of Coffee ringspot virus (CoRSV), the causing agent of coffee ringspot disease. Knowing the mite-host interaction and the variables that improve the development of the mite are important in order to manage the disease. The aim of this work was to study the relationships of cause and effect between water availability and leaf temperature on population fluctuation of B. yothersi on coffee plants Coffea Arabica L. Inside a greenhouse, plants under four levels of field capacity: 25, 40, 55 and 70% were arranged in two groups: (1) infestation of viruliferous B. yothersi with CoRSV and (2) no mite infestation. Following the transfer of mites to coffee plants, leaf temperature was measured daily in order to calculate the Daily Water Stress Index (DWSI). At the end of this experiment, the mites present on coffee plants were quantified and leaf samples were collected for leaf nitrogen content measurements. It was found that plants infested with B. yothersi indicated higher values of DWSI and lower levels of leaf nitrogen content when compared to non-infested plants. Furthermore, plants on higher water availability revealed higher populations of B. yothersi.
